This is a randomized prospective study to compare the efficacy of fully suppressive vs partially suppressive doses of L-thyroxine in shrinking abnormal thyroid tissue, and to evaluate changes in bone density which may occur in patients taking suppressive doses of L-thyroxine, and to determine if any documented adverse effects of L-thyroxine on peripheral organs can be minimized by using partially suppressive, rather than fully suppressive doses of L-thyroxine.